1. Field of the invention
This invention relates to rotary variable volume control devices for engines and pumps where axial reciprocation is created by the rotation of a central operating shaft.
2. Description of the prior art
In the axially controlled rotary engine class axial piston or vane motion is usually created by stationary cam surfaces which convert a rotary motion to an axial motion which is used to create variable volume pressure chambers in cylinders or compartments.
Among the numerous cam controlled axial piston engines the latest examples are found in U.S. Pat. Nos. 5,813,372 of Manthen, 5,209,190 of Paul, 4,287,858 of Anzalone and 4,022,167 of Kristansen. While most of these patents have a positive cam groove action, in U.S. Pat. No. 5,812,372 a somewhat simpler construction is shown, but the non-positive axial cams require a spring loaded cam follower action for engine starting.
In U.S. Pat. No. 5,429,084 of Cherry, cam operated axially sliding vanes are used to create variable volume pressure chambers. Though this concept is relatively simple, sealing and pressurized vane sliding are creating rather difficult problems to make this a wider scale practical solution. In U.S. Pat. No. 3,801,237 of Gotthold a bevel-gear-type vane control is shown, but in this two-ended control mechanism complexities, manufacturing difficulties and strength requirements/re its drawbacks.
In the axially controlled rotary engine class axial piston or vane motion is usually created by stationary cam surfaces which convert a rotary motion to an axial motion which is used to create variable volume pressure chambers in cylinders or compartments.
Among the numerous cam controlled axial piston engines the latest examples are found in U.S. Pat. Nos. 5,813,372 of Manthen, 5,209,190 of Paul, 4,287,858 of Anzalone and 4,022,167 of Kristansen. While most of these patents have a positive cam groove action, in U.S. Pat. No. 5,812,372 a somewhat simpler construction is shown, but the non-positive axial cams require a spring loaded cam follower action for engine starting.
In U.S. Pat. No. 5,429,084 of Cherry, cam operated axially sliding vanes are used to create variable volume pressure chambers. Though this concept is relatively simple, sealing and pressurized vane sliding are creating rather difficult problems to make this a wider scale practical solution. In U.S. Pat. No. 3,801,237 of Gotthold a bevel-gear-type vane control is shown, but in this two-ended control mechanism complexities, manufacturing difficulties and strength requirement are its drawbacks.
Bevel gears or bevel-gear-type differentials are used in various other rotary engine concepts for creating an oscillating vane motion in stationary cylindrical pressure chambers with a stationary vane set. Wang in his U.S. Pat. No. 4,539,941 is using opposing half-circular sector gears on an output shaft to convert an oscillating vane and bevel gear motion to a uniform speed output shaft rotation while Choi in his U.S. Pat. No. 6,186,098 is using a modified Scotch yoke principle where the ordinary power transmission slot and pin connection requires an extra complexity to transmit the rotary powered slot oscillation to a uniform motion bevel gear in mesh with another one on a perpendicular output shaft.
Brown in his U.S. Pat. No. 3,974,801 is using cylinders and pistons mounted on a rotating disk where the Piston reciprocation is created by a special ratio changing gear pair in a gear train which includes a differential gear for power output.
As becomes apparent later, in our disclosure crank pins are used on bevel gears or bevel-gear-type differentials in a novel-way to generate compound axial and rotating motions for controlling variable speed unidirectional vane rotations or axial piston reciprocations in ordinary cylinders.
The term xe2x80x9crotary energy converterxe2x80x9d can be applied to a large variety of devices where a variable volume pressure chamber is created in many different ways by a shaft rotation for the purpose of changing the pressure energy to a powered shaft rotation or in the reverse manner to convert a powered shaft rotation to a fluid pressure energy as found in pumps or compressors.
In our U.S. Pat. No. 5,501,182, titled xe2x80x9cPeristaltic Vane Device for Engines and Pumpsxe2x80x9d a radial rotating control motion is used to control the acceleration and deceleration of vanes in a main pressure chamber. The word peristaltic was used because of the similarity of flow characteristic as found in our digestive system. Therefore the words peristaltic wave, peristaltic step and peristaltic step factor are used again for various features. While the same differential gear controlled vane motion or peristaltic motion is found in the present invention, the variable motion controlling crankpin is on a bevel gear to provide an axial link connection to the reversing gear of a bevel-gear-type differential which provides same kind of vane acceleration-deceleration as the side gear control from the orbiting crank in our above mentioned invention. (FIGS. 17 and 18 where a toroidal pressure chamber is also shown as found in this invention.)
In a modified configuration the axially controlled crankarm of the reversing gear could have also a direct barrel cam control without the bevelgear control linkage which is reducing the length of this model.
In a somewhat different version of this invention the same bevel gear generated axial motion is readily applied to reciprocate the ordinary pistons in cylinders. Again,the application flexibility is possible here which includes rotating and stationary pressure chambers or cylinder blocks, engine or pumping versions, reversibility and self starting in steam engines and a choice of radial or face-to-face communication.
It has been recognized that most rotary engines are more compact and lighter than the in-line-piston engines but besides the size advantage the advantages listed for Wankel rotary engines are applicable also for our rotary engines: low weight to HP ratio, smooth vibrationless operation, quiet running, low cost and simplicity and no poppet valves are reducing friction and make the fresh charge and exhaust more effective.
Thus the general object in the present invention is to provide an axial control motion applicable to control the acceleration and deceleration of vanes in a main pressure chamber or using this axial motion to directly reciprocate ordinary pistons in cylinders to create variable volume pressure chambers for engine or pumping applications.
A more specific object in vane-type differential gear controlled rotary energy converters is using the reversing gear of the differential for linking a bevel gear orbiting crank controlled oscillation to an arm on said reversing gear which is in a limited angle mesh with side gears of the differential which is controlling the acceleration and deceleration of the vanes.
In another modified version the reversing gear crank arm on said differential gear controlled vane-type energy converter is functioning as a cam follower for a barrel-type cam groove which is controlling the acceleration and deceleration of vanes.
Another modified object is to use said bevel gear generated axial motion for axially reciprocating ordinary pistons in a rotating cylinder barrel for engine or pumping applications.
In a similar modified version said bevel gear generated axial motion is applied to reciprocate said pistons in a stationary cylinder block in which case the operating shaft is secured to the controlling bevel gear and to a rotating communication member which can have a radial or axial face-to-face port communication with stationary ports.
A further object in said piston-in-cylinder version for steam or external pressure engines is to provide self starting and reversibility options for cylinder numbers 2 or more.
A more detailed object for piston-type versions is to provide communication members adapted to any piston numbers or bevel gear ratios in steam and internal combustion engines, pumps and compressors.
A final general object is to provide constructional details for satisfying strength and bearing requirements and to offer relatively simple and compact positively controlled transmission options suited for engine and pumping applications of any size.